1. Field of the Invention
The present invention relates to a side member and bumper beam attaching structure.
2. Description of the Related Art
In general, side members are used on an underbody in order to increase the strength and rigidity of a vehicle body and extend in a longitudinal direction of the vehicle body to form a frame-like configuration. Bumper beams are provided at end portions of the side members to absorb an impact when the vehicle collides to thereby protect the vehicle body at the front and rear thereof.
In attaching a bumper beam to a side member, a substantially L-shaped bracket is disposed at an end portion of the side member in such a manner as to expand as viewed from the front or rear of the vehicle body. The bracket and the bumper beam are fixed together with bolts at outer positions of the side member and are then welded together.
When the bracket and the bumper beam are fixed together with bolts like this at the outer positions of the side member, the bolts are disposed at an interval which is equal to the width of the side member. In this case, a problem arises that a force generated when the vehicle collides becomes difficult to be transmitted efficiently to the cross section of the side member. To solve this problem, JP-A-10-250505 (Paragraph No. 0011, FIGS. 2 and 6) discloses a technique related to the structure of part of a vehicle body where a bumper is attached.
In the technique related to the structure of part of the vehicle body where a bumper is attached, two vertical walls of the side member having a rectangular closed cross section is held by a bracket from the outside at an end portion of the side member, and the outsides of the vertical walls and the bracket are arc welded together. Furthermore, bolts are disposed on the bracket at positions corresponding to inner positions of the side member so that a bumper beam is attached to the side member via the bolts so disposed.
According to this structure, the distance between the bolts for fixing the bracket and the bumper beam together becomes shorter, so that the deformation of the side member can be suppressed.
Incidentally, it is a general practice to attach a cross member to distal end portions of side members from the outside of the side members. Holding the distal end portions of the side members by brackets from the outside of the side members causes a problem that the attachment of members including the cross member to the distal end portions of the side members becomes troublesome. Namely, there occurs an interference of the brackets with the cross member at outside positions of the distal end portions of the side members. Therefore, in determining an attachment configuration for the cross member, not only the configuration of the distal end portion of the side member but also the configuration of the bracket need to be considered. This results in a problem that the efficiency of attachment work is deteriorated.